Chain-grate heat machine



Jan. l5, 1957 w. M. DUNCAN CHAIN-GRATE HEAT MACHINE Filed May 25, 1955 xii This invention`relvatesw generally to chain-grate machines of theftype'usedfin burning or heating Lcoal, agv

gregate, ore, refugendftheglike, nandfmorze. particularly tolthe grate supporting structure innsuchfa machine,

It will'be unlderstood'that a chainlgrat machinenessentiallycomprises a wide endless chain-loigraterforming links, suchI as lthose disclosed 'in United :States Patent No. 2,699,130. The chains are trained about drive sprockets at one end (generally the front) of the machine and about an idler drum or sprockets at the other end. The upper reach of the chain serves as a grate onto which fuel and other materials may be fed substantially continuously, the material being burned or heated as it is conveyed to the other end of the machine, where it is dumped automatically as the links move about the reverse bend to the lower reach. Wind boxes are usually mounted immediately below the upper reach to control the draft, which may be forced upwardly and induced downwardly.

Heretofore, it has been customary to support the upper reach of the grate upon longitudinal skid bars, but

with that system, considerable friction and wear occurs, j

and in down draft operation, the skids are heated to an extentsuch that they are seriously weakened and frequently fail. Accordingly, it is an object of the invention to provide an improved system for supporting chaingrate links as they move along the upper portion of a chain-grate heat machine.

Briey, the invention contemplates that the chain-grate links will be supported n hollow. rollers, which rollers are connected along one side of the machine to water inlet pipes and along the other side to water discharge devices. Preferably, the water outlets are constricted relative to the inlets and may have valves for controlling flow of the water or other coolant in accordance with the needs therefor. Also, the outlet end of each roller is provided with an air trap in the form of an opening located adjacent the inner periphery of the roller.

Other features of the invention will be in part apparent from and in part pointed out in the following detail description taken in connection with the accompanying drawings, in which:

Fig. 1 is a diagrammatic representation of typical chain-grate heat machine;

Fig. 2 is a transverse vertical section illustrating details of a chain-grate machine embodying the invention;

Fig. 3 is a detailed top plan view showing some of the chain-grate links and their supporting rollers;

Fig. 4 is a detail section at the outlet end of a roller taken on the line 4 4 of Fig. 5; and

Fig. 5 is a cross section of a roller looking toward the outlet end thereof.

Referring to Fig. l, the invention is particularly directed to a machine of the type having a plurality of chain-grate links generally designated 1, which form a relatively wide endless chain. For example, the links may be of the type disclosed in the UnitedStates patent of F. S. Simpson, No. 2,699,130, granted January ll, 1955. The chain is trained about front drive sprockets nited States Patent 0 2,777,429 Patented Jan, l5, 1957 3, which are driven on a horizontaltaxisby. anelectric motonorother suitable@owendevice.. At the A.other .end of thetmachine, there. is anidler. drumora series ofidler sprockets; 5,- and. the.. chain .extends .therebetween withA anA upper reach7-.and lowerreachglll The spacebetween the I upper ,and :lowenreaches -Aaccommodates. Aa series of .wind boxesA 11, which. are connected-.to..an air manifoldll,`

eachrwind '.hoxhavingv a.. gate valve,A ortheA like `for conv` trolling ,the. draft.rati that.\part l of. the..grate.` In. certain types ofoperationsuchr as sinteri'ng .or.agg`regating the., draft. is. usually, induced..fdownwardlyso. that the fines,

maybe collectedin. the windboxland reused.V

In a stoker, coal is burneduponthe .upper.reach.,'7., and

inother applicationsrock, ore. onrefusemayhe fed .upon the,upper .reacl`1,. as.from a .hopp.er13 :adjacent the ffront of-fthe,r`nachine, withrlwithnt adniixed fuel.y An. ig:V mter adjacent,the..hopper .initiates combustion, andlhe...

material; isl burned asl; its progresses toward.; the rear.. of

the machine. Ideal1ythelieatingoperation.is completed,-4

auch the., material; is automatically.; dumped.; as the links mavsbqatfthgerersebend5t;

The usual practice heretofore has been to provide skids or longitudinal bars for supporting the chain-grate links as they move from the drive sprockets toward the back of the machine along the upper reach, but this arrangement has not been entirely satisfactory, especially where the load is substantial and the draft is downward.

Referring now more particularly to Figs. 2 and 3, angle members 15 are shown to extend along the sides of the machine as part of the ixed framework, but the chain-grate links 1 are supported in their movement along the upper reach by a series of rollers 17. The rollers are journalled on supports 19 carried by the angle members 15, and these supports in turn may carry adjustable side plates 21 cooperable with the sides of the grate. The rollers are longitudinally spaced, as on twelve inch centers where the rollers are about three inches in diameter, so as to permit a draft therebetween. The draft is controlled by means of wind boxes below the upper reach, as indicated in Fig. l.

In accordance with this invention, each roller is a hollow tube having an inlet plug 23 and an outlet plug 25', which plugs have bearing extensions as illustrated. The bearing extensions on each side are received in roller bearings 27 and oil seals 29 may be disposed at opposite sides of the roller bearings to provide for sealed lubrication.

The inlet plug 23 further includes an axial bore 31, which opens into the hollow drum at one end and into a fixture 33 at its outer end. This fixture 33 is connected through a rotary joint 35 to a lixed inlet pipe 37. This pipe is connected to a longitudinal water manifold 39, the manifold being supported at 41 along one side of the machine.

The opposite end of each roller is also formed with a passage, the inner opening 43 of which is located adjacent the inner periphery of the drum. The passage then extends radially at 45 to an axial bore 47, which is closed at its inner end but otherwise communicates with an outlet pipe 49. The outlet pipe 49 preferably includes a conventional valve 51, the valve and pipe 49 rotating with the roller. The end of the pipe 49 enters a water carry off trough 53 extending along the other side of the machine. v

In operation, outlet valves 51 are adjusted to control the ow of cooling liquid, which normally would be water. The outlet is restricted in comparison with the inlet so that there is pressure within the roller, but the ow through each roller is adjusted along the machine with regard to the necessity for cooling. In general, the temperature of the grate is higher towards the back of the machine, hence the necessity for varying flow through the several rollers. Initially, air is trapped within a roller, but as the roller rotates, such trapped air is forced out by the entering water pressure when the opening43 is at an uppermost position.

From the foregoing description, it will be apparent to those skilled in the art that my method of supporting the chain-grate links affords radvantages over prior practice. The absence of sliding frictional engagement between the links and their supports reduces the power required to drive the machine and the wear upon moving parts. Moreover, the provision for circulation of a coolant permits the machine to be operated at relatively high temperature without danger of weakening load-sustaining portions of the machine. Indeed, these members may be formed relatively light weight in comparison with prior practice for this very reason.

Whereas one embodiment has been described in detail, it should be understood that the modications will suggest themselves to those skilled in the art; and the invention should not be considered so limited.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

In a chain-grate machine, a fixed supporting framework, a wide endless chain of grate-forming links, means supporting said chain grate so as to have generally horizontal upper and lower reaches and for moving the chain substantially continuously, the upper reach of chain constituting a continuous grate onto which material is fed at one end and upon which the material is heated as the chain moves, the supporting means of the upper reach of chain being constituted by a plurality of hollow rollers in horizontally spaced relationship from one another along and beneath the upper reach of the chain, each of said rollers being journalled at its ends on said framework transversely thereof to support a portion of the upper reach of chain, a water inlet manifold mounted on the framework along one side of the chain, rotary joints interconnecting one end of each roller with said inlet manifold, and each roller having a separate adjustable outlet valve connected at its other end, thereby to permit selec tive variation in the Water flow through individual rollers.

References Cited inthe tile of this patent UNITED STATES PATENTS 535,412 Richards Mar, 12, 1895 619,715 Bright Feb. Z1, 1899 877,610 Steinl Jan. 28, 1908 

